skip to content

Cambridge NERC Doctoral Training Partnerships

Graduate Research Opportunities
 

Lead Supervisor: Tom Lachlan-Cope, British Antarctic Survey

Co-Supervisor: Michael Herzog, University of Cambridge

Importance of the area of research concerned: 
The largest uncertainties of future climate prediction as highlighted by the International Panel on Climate Change (IPCC) report arises from the inability of models to correctly simulate clouds. The Southern Ocean, one of the cloudiest places in the planet, has been found to have the largest shortwave radiation biases within global models, as indicated in the Coupled Model Intercomparison Project 5 (CMIP 5). Errors in cloud parameterisation leading to poor representation in models has been suggested as the main reason for the current model biases over the Southern Ocean (Bodas-Salcedo et al., 2013). The lack of measurements of cloud properties, as well as of Cloud Condensation Nuclei (CCN) and Ice Nuclei (IN) at high latitude limits our ability to improve the modelling of clouds.
Project summary : 
This project will use a range of numerical models (WRF, WRF-Cchem, UKMO) to investigate how sensitive the climate system over Antarctica and the Southern Ocean to variations in Cloud Condensation Nuclei (CCN) and Ice Nucleating Particles (INP). Recent studies have revealed the possibility of new sources of these particles from the sea ice zone. These include the possibility that the sea ice, rather than the open water, is the major source of sea salt aerosols (Lachlan-Cope et al., 2016). The ultimate aim of the project is to identify the geographic areas, season of emission, and types of aerosols that would have the biggest impact on the climate of the southern hemisphere to inform future observational campaigns. Field work at high southern latitudes is very difficult and expensive so this work will make sure that limited resources are directed to the most important places.
What will the student do?: 
The student will use limited observations of aerosol, CCN and INP already taken at high latitudes, as well as models predicting emission for sea salt aerosol (Yang et al., 2008), to determine a possible map for the emission and variability of aerosols. This will be used to investigate the impact that the range aerosol emissions has on the climate within limited area models (WRF and WRF-Chem) before investigating the impact on climate models (UKMO). Using these model runs, the sensitivity of the models to a range of aerosol emissions scenarios can be determined and this will inform future observational campaigns. There might be an opportunity for the student to take part in an observational campaign in the Antarctic.
References: 
Bodas-Salcedo, A., Williams, K.D., Field, P.R., and Lock, A. P., 2012: The Surface Downwelling Solar Radiation Surplus over the Southern Ocean in the Met Office Model: The Role of Midlatitude Cyclone Clouds. J. Climate, 25, 7467–7486. doi: doi.org/10.1175/JCLI-D-11-00702.1.
Lachlan-Cope, T., Listowski, C., and O'Shea, S.,. 2016.The microphysics of clouds over the Antarctic Peninsula – Part 1: Observations, Atmos. Chem. Phys., 16, 15605-15617, doi:10.5194/acp-16-15605-2016, 2016.
Yang, X., Pyle, J. A., and Cox, R. A.: Sea salt aerosol production and bromine release: Role of snow on sea ice, Geophys. Res. Lett., 35 (L16815), doi:10.1029/2008gl034536, 2008.
Applying
You can find out about applying for this project on the British Antarctic Survey (BAS) page.